When communication sequences are encoded and embedded into radar emissions, the resulting radar-embedded communication (REC) waveforms change from pulse to pulse both during and across coherent processing intervals (CPIs). The resulting radar emissions are termed. ‘coding diverse’ or ‘waveform diverse’. Waveform diversity occurs whenever the radar waveform changes on a pulse-to-pulse basis, as in pulse-agile or adaptive radar in addition to coding diverse REC. Matched filtering of these different waveforms leads to different sidelobe structures, giving rise to the range sidelobe modulation (RSM) of clutter. The clutter RSM (C-RSM) induces residual clutter spread into the entire range-Doppler response, and thus reduces target detection performance. Filtering approaches exist that maximize the signal-to-interference-plus-noise-ratio (SINR) of pulse agile systems by joint range-Doppler processing. However, direct implementation of the maximum SINR approach to waveform diverse radar emissions, such as transmit-encoded. REC systems, leads to prohibitive computational complexity.
Accordingly, there exists a need for a reduced complexity optimal receiver for use with pulse agile/waveform diverse radar systems both pulse-to-pulse and CPI-to-CPI changing radar emissions.